 | April 1, 2000 |
High notes
Concept pushes for all-digital audio transmission
Who would believe that so many companies are so deeply concerned about our music-listening experience? Hardly a week goes by that we don't receive a pitch for a new audio technique. The latest to take the mound was Texas Instruments, pushing digital audio first for the PC and later for home entertainment. The technology, called True Digital Audio Amplifier (TDAA), moves the digital-to-analog conversion process into the component directly in front of the speaker coil. Thus the perfect stream of digital bits can march right up to the speaker. This presumably reduces the chances of interference or noise degrading the signal, as happens with analog signals. The company claims the technique yields a perceptible improvement.
However, we see problems. For starters, in the PC environment, USB is the interface of choice for such applications. But so far USB has proven less than reliable for real-time music delivery. TI claims to be solving the problem along with Microsoft. Secondly, if digital audio really makes sense, wouldn't we need an amplifier in every speaker? Yet most digital speaker schemes put the amplifier in a single speaker, such as a subwoofer, and then revert to low-cost analog connections for the other speakers.
Regardless of where the data conversion takes place, the quality—or, in engineering terms, the "precision"—of the digital-to-analog conversion governs sound quality. Analog Devices is offering a new pair of converter ICs for DVD players, the AD1852 and 1854, which provide 113 to 117 dB of dynamic range. Audiophiles may need no translation, but for the rest of us, the company claims this dynamic range will "immerse the user in true-to-life dynamic audio."
—Maury Wright, Executive Editor
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